Lights Don't Work in Medium+ Render

I created a 3D model and added two spotlights to it. When I do the render in Low or Draft mode the lights show up. But when I run the render in Medium or anything higher they lights are gone.

I have the sun turned on and the sky turned on with illumination. This darn thing takes almost 2 hours to render in Presentation mode so it's very frustrating to get through a run only to find out the lights are out.

Any suggestions?

OKAY FOUND IT...you have to turn the light up. And when I say up I really mean up. Tried 3000 and that was kind of bright. Next tried 800 and that was much nicer but still a little on the bright side. So I'm going to try something a little lower once this next render is through. Once again, the docs, web posts, just about everything I looked at for answers never mentioned that you need to turn the lights up so bright in order to work with the sun and sky switched on.